Mounting fitting of heat sink and method of removing the same

ABSTRACT

A mounting fitting of a heat sink of the present invention is unitarily formed of a first spring, a second spring, a central part disposed in the boundary between the first and second springs, a first arm connecting to an end of the first spring on the opposite side to the fulcrum, a second arm connecting to an end of the second spring on the opposite side to the fulcrum, a plate part formed in the second spring and near the second arm and having a small hole, and a stopper formed in a space between the second spring and arm. The fitting allows safe removing of the heat sink.

FIELD OF THE INVENTION

[0001] The present invention relates to a fitting for mounting a coolingapparatus for cooling a micro-processing unit (MPU) used for a personalcomputer or the like to the MPU, and a removing method of the fitting.

BACKGROUND OF THE INVENTION

[0002] A heating value of an electronic instrument has recentlyincreased in response to high integration of electronic components suchas a semiconductor or increase of frequency of an operating clock. Aproblem of how junction temperatures of respective electronic componentsare kept within an operating temperature range becomes serious fornormally operating the electronic components.

[0003] Especially, the integration and frequency of the MPU areextremely increased, so that measures against heat radiation becomeimportant for stabilizing an operation and securing the operating life.

[0004] The heat of the MPU mounted to an MPU socket is radiated by aheat sink and a fan having a motor. The heat sink increases a large heatradiating area and exchanges the heat with a refrigerant such as air.The fan forcibly feeds the refrigerant such as the air to the heat sink.Generally, the heat sink is removably mounted to MPU so that the MPU canbe replaced with a new MPU when the MPU fails or needs to be replaced.

[0005] Examples of a mounting structure and a mounting method of aconventional heat sink to an MPU are described with reference to FIG. 7through FIG. 10.

[0006]FIG. 7 is a perspective view of an entire MPU—heat sink—fanassembly using a mounting fitting of the conventional heat sink, andFIG. 8 is a perspective view of the mounting fitting of the conventionalheat sink. FIG. 9A, FIG. 9B, and FIG. 9C are sectional views of the heatsink and the fitting, and are used for illustrating a mounting method ofthe mounting fitting of the conventional heat sink. FIG. 10A, FIG. 10B,and FIG. 10C are sectional views of the heat sink and the fitting, andare used for illustrating a removing method of the mounting fitting ofthe conventional heat sink.

[0007] In FIG. 7 and FIG. 9A, MPU socket 1 is entirely formed in a plateshape having a predetermined thickness, and has first locking claw 1 aand second locking claw 1 b on its one side and the other side,respectively. MPU 2 of a pin grid array (PGA) type package generatingheat is mounted on MPU socket 1, and heat sink 13 touches on the uppersurface of MPU 2 and radiates heat from MPU 2.

[0008] Heat sink 13 has base part 13 a in its lower part and fin part 13b disposed on base part 13 a. Fin part 13 b receives the heat conductedfrom base part 13 a and radiates the heat to ambient air.

[0009] Fan 4 is disposed on heat sink 13 and forcibly air-cools the heatof heat sink 13. Mounting fitting 15 is disposed on beat sink 13 andfixes heat sink 13.

[0010] Mounting fitting 15 is entirely formed in an M shape. Mountingfitting 15 comprises the following elements:

[0011] (a) first spring 15 a and second spring 15 b disposed in theintermediate positions;

[0012] (b) fulcrum 15 c that is disposed in the boundary between firstspring 15 a and second spring 15 b and presses heat sink 13;

[0013] (c) first arm 15 d connecting to an end of first spring 15 a onthe opposite side to fulcrum 15 c;

[0014] (d) second arm 15 e connecting to an end of second spring 15 b onthe opposite side to fulcrum 15 c;

[0015] (e) plate part 15 f disposed on first arm 15 d and having a firstlocking hole engaging with first locking claw 1 a;

[0016] (f) plate part 15 g disposed on second arm 15 e and having asecond locking hole engaging with second locking claw 1 b;

[0017] (g) plate part 15 h having a square hole and formed near thedirectly above part of plate part 15 g having the second locking hole.Bar 6 is a precision screwdriver for removal, and is thin and highlyrigid.

[0018] A cooling operation of a cooling apparatus comprising thecomponents discussed above is briefly described. The heat generated fromMPU 2 is received by the bottom surface of base part 13 a, and diffusesinside base part 13 a. The heat then conducts to fin part 13 bfunctioning as a heat radiating fin, is forcibly air-cooled by fan 4,and is radiated to the ambient air.

[0019] Referring to FIG. 9A, FIG. 9B, and FIG. 9C, there is described amethod of crimping and fixing heat sink 13 onto MPU 2.

[0020] Firstly, heat sink 13 is placed on MPU 2 mounted to MPU socket 1,mounting fitting 15 is placed on heat sink 13, and plate part 15 fhaving the first locking hole is hooked on first locking claw 1 a ofsocket 1 (FIG. 9A).

[0021] Then, while fulcrum 15 c of mounting fitting 15 is in contactwith the upper face of base part 13 a of heat sink 13, a load (P1 shownin FIG. 9B) is applied to second spring 15 b to press it down until thetip of second arm 15 e contacts with the upper part of second lockingclaw 1 b of socket 1 (FIG. 9B). When second spring 15 b is furtherpressed down, the lower part of second arm 15 e touches on the slope (Sshown in FIG. 9B) of the upper part of second locking claw 1 b to opensecond arm 15 e. Therefore, plate part 15 g having the second lockinghole is finally hooked on second locking claw 1 b (FIG. 9C). Fan 4 maybe mounted on heat sink 13 after that, or may be previously mounted onheat sink 13.

[0022] Referring to FIG. 10A, FIG. 10B, and FIG. 10C, there is describeda method of removing heat sink 13. Firstly, bar 6 is inserted into thesquare hole in plate part 15 h of mounting fitting 15, and a load (P2shown in FIG. 10A) is applied to bar 6 to press bar 6 down until thelower end of plate part 15 g having the second locking hole comes belowthe lower end of second locking claw 1 b of socket 1 (FIG. 10A).

[0023] Then, a load (M2 shown in FIG. 10B) is applied to bar 6 with loadP2 applied, thereby bending second arm 15 e of mounting fitting 15outwardly (FIG. 10B). When load P2 for pressing down second arm 15 e isthen removed, plate part 15 g having the second locking hole comes offsecond locking claw 1 b due to restoring forces of first spring 15 a andsecond spring 15 b of mounting fitting 15 (FIG. 10C). When plate part 15f having the first locking hole hooked on first locking claw 1 a isremoved, entire mounting fitting 15 is removed to allow heat sink 13 tobe removed.

[0024] In another embodiment, mounting fitting 15 may be a linkmechanism assembly comprising a plurality of components as shown by aperspective view of a mounting fitting of another conventional heat sinkof FIG. 11. FIG. 12 is a perspective view of an entire MPU—heat sink—fanassembly using the mounting fitting of the heat sink of FIG. 11.

SUMMARY OF THE INVENTION

[0025] A substantially M-shaped mounting fitting made of a plate-likeelastic material crimps and fixes a heat sink onto a heating element.The heating element is mounted on a socket, and the heat sink diffusesheat of the heating element. The mounting fitting of the heat sinkcomprises the following elements:

[0026] a first spring;

[0027] a second spring coupling to the first spring;

[0028] a central part that is a boundary part between the first springand the second spring and finctions as a fulcrum for pressing the heatsink;

[0029] a first arm connecting to an end of the first spring on theopposite side to the fulcrum;

[0030] a second arm connecting to an end of the second spring on theopposite side to the fulcrum;

[0031] a plate part having a small hole and formed in the second springand near the second arm; and

[0032] a stopper formed in a space sandwiched between the second springand the second arm.

BRIEF DESCRIPTION OF THE DRAWINGS

[0033]FIG. 1 is a perspective view of an entire MPU—heat sink—fanassembly using a mounting fitting of a heat sink in accordance withexemplary embodiment 1 of the present invention.

[0034]FIG. 2 is a perspective view of the mounting fitting of the heatsink in accordance with exemplary embodiment 1.

[0035]FIG. 3A, FIG. 3B, and FIG. 3C are sectional views of the heat sinkand the fitting in accordance with exemplary embodiment 1, which areused for illustrating a removing method of the mounting fitting of theheat sink.

[0036]FIG. 4A and FIG. 4B are perspective views the other configurationsof the mounting fitting of the heat sink in accordance with exemplaryembodiment 1.

[0037]FIG. 5A is a perspective view of a mounting fitting of a heat sinkin accordance with exemplary embodiment 2 of the present invention.

[0038]FIG. 5B is a sectional view of the heat sink and the fitting inaccordance with exemplary embodiment 2, which is used for illustrating aremoving method of the mounting fitting of the heat sink.

[0039]FIG. 6A is a perspective view of a mounting fitting of a heat sinkin accordance with exemplary embodiment 3 of the present invention.

[0040]FIG. 6B shows engagement between the mounting fitting inaccordance with exemplary embodiment 3 and a removing tool.

[0041]FIG. 7 is a perspective view of an entire MPU—heat sink—fanassembly using a mounting fitting of a conventional heat sink.

[0042]FIG. 8 is a perspective view of the mounting fitting of theconventional heat sink.

[0043]FIG. 9A, FIG. 9B, and FIG. 9C are sectional views of theconventional heat sink and fitting, which are used for illustrating amounting method of the mounting fitting of the heat sink.

[0044]FIG. 10A, FIG. 10B, and FIG. 10C are sectional views of theconventional heat sink and fitting, which are used for illustrating aremoving method of the mounting fitting of the heat sink.

[0045]FIG. 11 is a perspective view of a mounting fitting of anotherconventional heat sink.

[0046]FIG. 12 is a perspective view of an entire MPU—heat sink—fanassembly using the mounting fitting of the conventional heat sink ofFIG. 11.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0047] Exemplary embodiments of the present invention will be describedhereinafter with reference to the accompanying drawings.

EXEMPLARY EMBODIMENT 1

[0048]FIG. 1 is a perspective view of an entire MPU—heat sink—fanassembly using a mounting fitting of a heat sink in accordance withexemplary embodiment 1 of the present invention. FIG. 2 is a perspectiveview of the mounting fitting of the heat sink in accordance withexemplary embodiment 1. In these drawings, same elements used in theprior art are denoted with the same reference number.

[0049] In FIG. 1, FIG. 2, FIG. 3A, FIG. 3B, and FIG. 3C, MPU socket 1has a predetermined thickness, is formed in a plate shape, and has firstlocking claw 1 a at its one side and second locking claw 1 b at theother side. MPU socket 1 is sold as a standard product by many connectormanufactures. MPU 2 of a PGA type package generating heat is mounted onthe upper surface of MPU socket 1. Heat sink 3 touches on MPU 2,receives heat from MPU 2, and radiates the heat. Heat sink 3 has basepart 3 a and fin part 3 b that receives the heat from base part 3 a andradiates the heat to the ambient air.

[0050] Fan 4 forcibly air-cools heat of heat sink 3. One fan 4 is usedin the present embodiment; however, fan 4 is not necessarily required inan environment in which convection of the ambient air can be expected tocool fin part 3 b. A plurality of fans may be used as necessary. Whenfan 4 is used, preferably, fan 4 is previously engaged with heat sink 3in a predetermined positional relation in a method such as screwing,adhering, or snap fitting. A subsequent assembling process can thus beperformed smoothly.

[0051] Mounting fitting 5 is installed on heat sink 3 to press and fixheat sink 3 to MPU 2. Mounting fitting 5 is entirely formed as anM-shaped plate as shown in FIG. 2, and manufactured by bending a platematerial. An elastic material such as stainless steel for a spring orberyllium copper is preferably used as a material of mounting fitting 5because the elastic material has a high elastic limit and withstands alarge load.

[0052] Mounting fitting 5 comprises the following elements:

[0053] (a) first spring 5 a and second spring 5 b in the central part;

[0054] (b) fulcrum 5 c that is a boundary part between first spring 5 aand second spring 5 b and presses heat sink 3;

[0055] (c) first arm 5 d connecting to an end of first spring 5 a on theopposite side to fulcrum 5 c;

[0056] (d) second arm 5 e connecting to an end of second spring 5 b onthe opposite side to fulcrum 5 c;

[0057] (e) plate part 5 f disposed in first arm 5 d and having a firstlocking hole engaging with first locking claw 1 a;

[0058] (f) plate part 5 g disposed in second arm 5 e and having a secondlocking hole engaging with second locking claw 1 b.

[0059] Plate part 5 i having a small hole is disposed in a part ofsecond spring 5 b near second arm 5 e, and a tongue-like stopper 5 j israised inwardly in second arm 5 e.

[0060] A region from the part of second spring 5 b including plate part5 i to second arm 5 e has a width larger than that of other part ofsecond spring 5 b. This region is bent, receives a force as describedlater when mounting fitting 5 is removed from MPU socket 1, and has asmall essential width because of existence of plate part 5 i having thesmall hole and stopper 5 j. However, the width of the region isincreased, thereby compensating strength of the region to prevent thedeformation. Mounting fitting 5 may have the same width entirely basedon a relation between a force of mounting fitting 5 for pressing heatsink 3 on MPU 2 and the strength of mounting fitting 5, and mountingfitting 5 may have a wider part and a narrower part depending on theholes and bending.

[0061] The end of first arm 5 d on the side of plate part 5 f having thefirst locking hole and the end of second arm 5 e on the side of platepart 5 g having the second locking hole are bent toward the outside ofmounting fitting 5. This structure allows smooth mounting of mountingfitting 5 to MPU socket 1 as described later.

[0062] In mounting fitting 5, first spring 5 a and second spring 5 bmainly elastically deform, a balance between a moment of a force byfirst spring 5 a and a moment of a force by second spring 5 b aboutfulcrum 5 c is struck. The length of first spring 5 a does not need tobe equal to that of second spring 5 b, but the lengths of the springsare preferably designed so that fulcrum 5 c is disposed directly aboveMPU 2. That is because shifting of fulcrum 5 c from the direct aboveposition of MPU 2 can cause inclined mounting of heat sink 3.

[0063] The configuration of mounting fitting 5 is not limited to theconfiguration shown in FIG. 2. FIG. 4A and FIG. 4B are perspective viewsof the other configurations of the mounting fitting of heat sink 3 inaccordance with exemplary embodiment 1 of the present invention. Fulcrum5 c need not to have a line shape, and may have a plane shape, or apoint shape formed by partially machining the plate material into aspherical shape, as shown in FIG. 4A. Plate part 5 i having the smallhole may extend into second arm 5 e as shown in FIG. 4A. In such aconfiguration, when the boundary between second spring 5 b and secondarm 5 e is bent in manufacturing mounting fitting 5 by press working,the outline of plate part 5 i can be prevented from deforming. Stopper 5j may be formed in not only second arm 5 e but also second spring 5 b asshown in FIG. 4B.

[0064] A cooling operation of a cooling apparatus of the presentembodiment and a method of crimping and fixing heat sink 3 onto MPU 2with the mounting fitting are not described because they are similar tothose of the prior art.

[0065] Referring to FIG. 3A, FIG. 3B, and FIG. 3C, there is described amethod of removing heat sink 3. FIG. 3A, FIG. 3B, and FIG. 3C aresectional views of the heat sink and the fitting in accordance withexemplary embodiment 1 of the present invention, which are used forillustrating a removing method of the mounting fitting of the heat sink.

[0066] Bar 6 in the drawings is a tool used for removal, for example aflat tip screwdriver for common home use, and has a tapered tip and highrigidity.

[0067] Firstly, bar 6 is inserted into the small hole in plate part 5 iof mounting fitting 5, and the tip of bar 6 is butted on stopper 5 j. Ahand having bar 6 applies a load (F shown in FIG. 3A) to second spring 5b of mounting fitting 5 to press down second spring 5 b until the lowerend of plate part 5 g having the second locking hole of mounting fitting5 comes below the lower end of second locking claw 1 b of socket 1 (FIG.3A).

[0068] Then, when the hand applies a load to bar 6 in the P direction ofFIG. 3B with load F applied, a force works for bending second arm 5 eoutwardly about plate part 5 i (FIG. 3B).

[0069] When load F for pressing down second spring 5 b is then removed,plate part 5 g having the second locking hole comes off second lockingclaw 1 b of socket 1 due to restoring forces of first spring 5 a andsecond spring 5 b (FIG. 3C). When plate part 5 f having the firstlocking hole hooked on first locking claw 1 a is removed, entiremounting fitting 5 is removed to allow heat sink 3 to be removed.

[0070] Bar 6 is inserted into the small hole in plate part 5 i, the tipof bar 6 is strongly butted on stopper 5 j, and the removing work canthus be performed stably, so that bar 6 does not come off and anelectric component is not damaged during the removing work.

[0071] In the above descriptions, plate part 5 f disposed in first arm 5d and having a first locking hole is engaged with first locking claw 1 aof the socket. Plate part 5 g disposed in second arm 5 e and having asecond locking hole is engaged with second locking claw 1 b of thesocket.

[0072] However, plate part 5 f disposed in first arm 5 d may have afirst locking claw and may be engaged with first locking hole 1 a of thesocket. Plate part 5 g disposed in second arm 5 e may have a secondlocking claw and may be engaged with second locking hole 1 b of thesocket.

EXEMPLARY EMBODIMENT 2

[0073]FIG. 5A is a perspective view of a mounting fitting of a heat sinkin accordance with exemplary embodiment 2 of the present invention. FIG.5B is a sectional view of the heat sink and the fitting in accordancewith exemplary embodiment 2, which is used for illustrating a removingmethod of the mounting fitting of the heat sink. Numbers in the drawingsare the same as those used in embodiment 1, and are not described.

[0074] Mounting fitting 5 includes plate part 5 i having the small holeand stopper 5 j in embodiment 1; however, instead of plate part 5 i andstopper 5 j, plate part 5 k having a substantially-pocket-shaped openingis formed outside second arm 5 e in embodiment 2.

[0075] For removing heat sink 3, bar 6 is inserted into plate part 5 khaving the substantially pocket shaped opening as shown in FIG. 5B. Theother removing processes are the same as those in embodiment 1.

[0076] Bar 6 can interfere with fan 4 depending on the position or thesize of fan 4 during the removing work in embodiment 1; however, inembodiment 2, the removing work can advantageously be performed with bar6 further separated from fan 4, so that bar 6 hardly interferes with fan4.

EXEMPLARY EMBODIMENT 3

[0077]FIG. 6A is a perspective view of a mounting fitting of a heat sinkin accordance with exemplary embodiment 3 of the present invention. FIG.6B shows engagement between the mounting fitting in accordance withexemplary embodiment 3 and a removing tool. Numbers in the drawings arethe same as those used in embodiment 1, and are not described.

[0078] Mounting fitting 5 includes plate part 5 i having the small holeand stopper 5 j in embodiment 1; however, instead of plate part 5 i andstopper 5 j, plate part 5 l having a groove extending from second arm 5e to second spring 5 b as shown in FIG. 6A is formed in embodiment 3.Plate part 5 l having the groove on the second arm 5 e side has a widthdecreasing with approach to plate part 5 g having the second lockinghole (substantial triangle). A cross tip screwdriver is used as bar 6 inembodiment 3.

[0079] For removing heat sink 3, as shown in FIG. 6B, plate part 5 lhaving the groove is engaged with the tip of bar 6. Subsequent removingprocesses are the same as those in embodiment 1.

[0080] Bar 6 can interfere with fan 4 depending on the position or thesize of fan 4 during the removing work in embodiment 1; however, inembodiment 3, the removing work can advantageously be performed with bar6 further separated from fan 4, so that bar 6 hardly interferes with fan4. Additionally, the configuration of mounting fitting 5 is notcomplicated differently from embodiment 2, so that the mounting fittingcan be easily manufactured.

[0081] In the mounting fitting in accordance with embodiment 1 of thepresent invention, plate part 5 i having the small hole functioning as afurculum of bar 6 used for the removing work is disposed in secondspring 5 b and near second arm 5 e, and stopper 5 j is disposed in aspace sandwiched between second spring 5 b and second arm 5 e.Therefore, in removing heat sink 3, bar 6 can be inserted from thedirect above part of heat sink 3, and the removing work is allowed evenin a small space. Safe and certain removing work is allowed in a stablestate of bar 6.

[0082] Plate part 5 k having the substantially pocket shaped opening isformed outside second arm 5 e in embodiment 2, so that bar 6 can beinserted from the direct above part of heat sink 3 in removing heat sink3 to allow certain removing work.

[0083] Plate part 5 l having a groove extending from second arm 5 e tosecond spring 5 b is formed in embodiment 3, so that bar 6 can beinserted from the direct above part of heat sink 3 in removing heat sink3 to allow certain removing work.

What is claimed is:
 1. A substantially M-shaped mounting fitting made ofa plate-like elastic material, said mounting fitting crimping and fixinga heat sink onto a heating element, the heat sink diffusing heat of theheating element mounted on a socket, said mounting fitting of the heatsink comprising: a first spring; a second spring coupling to said firstspring; a central part being a boundary part between said first springand said second spring and functioning as a fulcrum for pressing theheat sink; a first arm coupling to an end of said first spring on theopposite side to the fulcrum; a second arm coupling to an end of saidsecond spring on the opposite side to the fulcrum; a plate part formedin said second spring and near said second arm, and having a small hole;and a stopper formed in a space sandwiched between said second springand said second arm.
 2. A mounting fitting of a heat sink according toclaim 1, wherein said stopper is formed in said second arm.
 3. Amounting fitting of a heat sink according to claim 1, wherein saidstopper is formed in said second spring.
 4. A removing method of asubstantially M-shaped mounting fitting made of a plate-like elasticmaterial, the mounting fitting crimping and fixing a heat sink onto aheating element, the heat sink diffusing heat of the heating elementmounted on a socket, the mounting fitting of the heat sink comprising: afirst spring; a second spring coupling to the first spring; a centralpart being a boundary part between the first spring and the secondspring and functioning as a fulcrum for pressing the heat sink; a firstarm coupling to an end of the first spring on the opposite side to thefulcrum; a second arm coupling to an end of the second spring on theopposite side to the fulcrum; a plate part formed in the second springand near the second arm, and having a small hole; and a stopper formedin a space sandwiched between the second spring and the second arm, saidremoving method comprising: inserting a bar-like tool into the platepart having the small hole, the tool having a cross section shapeallowing insertion into the plate part having the small hole; andbending the second arm outwardly with a tip of the tool while pressingdown the stopper with the tool.
 5. A substantially M-shaped mountingfitting made of a plate-like elastic material, said mounting fittingcrimping and fixing a heat sink onto a heating element, the heat sinkdiffusing heat of the heating element mounted on a socket, said mountingfitting of the heat sink comprising: a first spring; a second springcoupling to said first spring; a central part being a boundary partbetween said first spring and said second spring and functioning as afulcrum for pressing the heat sink; a first arm coupling to an end ofsaid first spring on the opposite side to the fulcrum; a second armcoupling to an end of said second spring on the opposite side to thefulcrum; and a plate part formed on an outer surface of said second armand having a bag-like and substantially pocket shaped opening.
 6. Aremoving method of a substantially M-shaped mounting fitting made of aplate-like elastic material, the mounting fitting crimping and fixing aheat sink onto a heating element, the heat sink diffusing heat of theheating element mounted on a socket, the mounting fitting of the heatsink comprising: a first spring; a second spring coupling to the firstspring; a central part being a boundary part between the first springand the second spring and functioning as a fulcrum for pressing the heatsink; a first arm coupling to an end of the first spring on the oppositeside to the fulcrum; a second arm coupling to an end of the secondspring on the opposite side to the fulcrum; and a plate part formed onan outer surface of the second arm and having a bag-like andsubstantially-pocket-shaped opening, said removing method comprising:inserting a bar-like tool into the plate part having the small hole, thetool having a cross section shape allowing insertion into the plate parthaving the small hole; and bending the second arm outwardly with a tipof the tool while pressing down the stopper with the tool.
 7. Asubstantially M-shaped mounting fitting made of a plate-like elasticmaterial, said mounting fitting crimping and fixing a heat sink onto aheating element, the heat sink diffusing heat of the heating elementmounted on a socket, said mounting fitting of the heat sink comprising:a first spring; a second spring coupling to said first spring; a centralpart being a boundary part between said first spring and said secondspring and functioning as a fulcrum for pressing the heat sink; a firstarm coupling to an end of said first spring on the opposite side to thefulcrum; a second arm coupling to an end of said second spring on theopposite side to the fulcrum; and a plate part formed in a region from apart of said second spring near said second arm to a part of said secondarm near said second spring, and including a groove having widthdecreasing with approach to an end of said the second arm.
 8. A removingmethod of a substantially M-shaped mounting fitting made of a plate-likeelastic material, the mounting fitting crimping and fixing a heat sinkonto a heating element, the heat sink diffusing heat of the heatingelement mounted on a socket, the mounting fitting of the heat sinkcomprising: a first spring; a second spring coupling to the firstspring; a central part being a boundary part between the first springand the second spring and functioning as a fulcrum for pressing the heatsink; a first arm coupling to an end of the first spring on the oppositeside to the fulcrum; a second arm coupling to an end of the secondspring on the opposite side to the fulcrum; and a plate part formed in aregion from a part of said second spring near said second arm to a partof said second arm near said second spring, and including a groovehaving width decreasing with approach to an end of said the second arm,said removing method comprising: inserting a bar-like tool having atapered tip and a recessed part in the tip into the plate part havingthe groove of the mounting fitting of the heat sink so that the platepart having the groove engages with the recessed part; and bending thetip of the tool outwardly while pressing down the plate part having thegroove with the tool.